Cohort Profile: Mandela's children: The 1990 birth to twenty study in South Africa

Background: There is a high and increasing prevalence of overweight and obesity in South Africans of all ages. Risk factors associated with overweight and obesity must be identified to provide targets for intervention. Objective: To identify the demographic, socio-economic and behavioural factors associated with body mass index (BMI) in middle-aged black South African men and women. Methods: Data on demographic and socio-economic factors were collected via questionnaire on 1027 men and 1008 women from Soweto Johannesburg, South Africa. Weight and height were measured and BMI was determined. Behavioural factors included tobacco use and consumption of alcohol, and physical activity data were collected using the Global Physical Activity Questionnaire. Menopausal status was determined for the women, and HIV status was available for 93.6% of the men and 39.9% of the women. Results: Significantly more women were overweight or obese than men (87.9 vs. 44.9%). Smoking prevalence (current or former) and minutes spent in moderate to vigorous intensity physical activity was significantly different between the sexes (both p < 0.0001). In the final hierarchical model, marital status (+ married/cohabiting), household asset score (+), current smoking (-), moderate to vigorous physical activity (-) and HIV status (- HIV infected) significantly contributed to 26% of the variance in BMI in the men. In the women, home language (Tswana-speaking compared to Zulu-speaking), marital status (+ unmarried/cohabiting), education (-), current smoking (-) and HIV status (- HIV infected) significantly contributed to 14% of the variance in BMI. Conclusions: The sex difference in BMI and the prevalence of overweight and obesity between black South African men and women from Soweto, as well as the sex-specific associations with various demographic, socio-economic and behavioural factors, highlight the need for more tailored interventions to slow down the obesity epidemic.

Section: Methodsmentioning

confidence: 99%

Demographic, socio-economic and behavioural correlates of BMI in middle-aged black men and women from urban Johannesburg, South Africa

Micklesfield

Kagura

Munthali

et al. 2018

“…Fortuitously they covered West, East and South Africa and represented rural and urban settings. Six study centres in four SSA countries were involved in Phase 1 of the AWI-Gen study: in South Africa, the MRC/Wits Agincourt HDSS [23], Dikgale HDSS [24] and the Soweto centre located within the MRC/Wits Developmental Pathways for Health Research Unit [20]; in Kenya the African Population and Health Research Center HDSS in Nairobi [25]; in Ghana the Navrongo HDSS in the Navrongo Health Research Centre [26]; and in Burkina Faso the Nanoro HDSS hosted by the Institut de Recherche en Sciences de la Santé Clinical Research Unit [27]. The study is coordinated by the AWI-Gen Collaborative Centre based at the Sydney Brenner Institute for Molecular Bioscience, University of the Witwatersrand in Johannesburg, South Africa.…”

Section: Methodsmentioning

confidence: 99%

“…At the Soweto centre, based in Johannesburg, female participants between the ages of 40 and 60 years at the time of data collection were recruited from an existing cohort of caregivers called ‘Birth to 20 plus’ (BT20+) [20]. Approximately 700 of the women selected from this cohort were also part of the ‘Study of Women Entering and Endocrine Transition’ (SWEET) [28].…”

Section: Methodsmentioning

confidence: 99%

“…The AWI-Gen partnership leverages unique strengths of the INDEPTH health and demographic surveillance systems network [19] and the MRC/Wits Developmental Pathways for Health Research Unit (DPHRU) in Soweto, Johannesburg [20], to access established frameworks for population-based research. These include infrastructure for longitudinal and cross-sectional field research, experience in establishing community engagement and retention programmes, and facilities in which clinical history, medical examinations, and collection of blood and urine samples can be carried out.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Genomic and environmental risk factors for cardiometabolic diseases in Africa: methods used for Phase 1 of the AWI-Gen population cross-sectional study

Ali

Soo

Agongo

et al. 2018

152

There is an alarming tide of cardiovascular and metabolic disease (CMD) sweeping across Africa. This may be a result of an increasingly urbanized lifestyle characterized by the growing consumption of processed and calorie-dense food, combined with physical inactivity and more sedentary behaviour. While the link between lifestyle and public health has been extensively studied in Caucasian and African American populations, few studies have been conducted in Africa. This paper describes the detailed methods for Phase 1 of the AWI-Gen study that were used to capture phenotype data and assess the associated risk factors and end points for CMD in persons over the age of 40 years in sub-Saharan Africa (SSA). We developed a population-based cross-sectional study of disease burden and phenotype in Africans, across six centres in SSA. These centres are in West Africa (Nanoro, Burkina Faso, and Navrongo, Ghana), in East Africa (Nairobi, Kenya) and in South Africa (Agincourt, Dikgale and Soweto). A total of 10,702 individuals between the ages of 40 and 60 years were recruited into the study across the six centres, plus an additional 1021 participants over the age of 60 years from the Agincourt centre. We collected socio-demographic, anthropometric, medical history, diet, physical activity, fat distribution and alcohol/tobacco consumption data from participants. Blood samples were collected for disease-related biomarker assays, and genomic DNA extraction for genome-wide association studies. Urine samples were collected to assess kidney function. The study provides base-line data for the development of a series of cohorts with a second wave of data collection in Phase 2 of the study. These data will provide valuable insights into the genetic and environmental influences on CMD on the African continent.

“…Gradidge’s thesis tests this hypothesis through secondary analyses of 10-year prospective data from the caregivers of the Birth-to-Twenty longitudinal cohort study [5]. Over this 10 year follow-up period, the prevalence of obesity increased by 29–66% [6], while the prevalence of MetS in this same cohort at baseline was as high as 50%.…”

Section: The Problem Of Obesity and Cardiometabolic Risk In South Afrmentioning

confidence: 99%

Addressing the problem of obesity and associated cardiometabolic risk in black South African women – time for action!

Goedecke

2017

The PhD thesis of Gradidge, entitled ‘Factors associated with obesity and metabolic syndrome in an ageing cohort of black women living in Soweto, Johannesburg (Study of Women in and Entering Endocrine Transition [SWEET])’, attempts to understand the determinants of obesity and metabolic syndrome (MetS) in a population of urban-dwelling black South African women. A conceptual framework is presented, which positions obesity as the central risk factor for MetS, and includes the possible influence of socioeconomic status, lifestyle behaviours and body size perceptions, as key determinants of obesity. This commentary focuses on the two main findings of Gradidge’s thesis, namely, (i) physical activity and sedentary behaviour, and (ii) body composition and adiponectin, as risk factors for obesity and MetS in black South African women. Despite a high prevalence of obesity (48%), Gradidge showed that 75% of the women taking part in the study were meeting WHO guidelines on physical activity. This commentary suggests that the relationship between physical activity and cardiometabolic risk may be confounded by socioeconomic status. Alternatively, the intensity, and not necessarily the volume, of activity, as well as high rates of sedentary behaviour are posited as important determinants of obesity and MetS in black South African women. Accordingly, this commentary questions the veracity of the WHO guidelines on physical activity in developing countries, where most women meet the guidelines but have very poor cardiorespiratory fitness, are obese and are at high risk of MetS. Gradidge also showed that the most consistent and significant correlate of MetS in this cohort of middle-aged women was low serum levels of adiponectin. This commentary highlights various lifestyle interventions that have been shown to increase adiponectin levels. Finally, the importance of immediate action to address the problem of obesity and MetS is emphasised.